FTIR study of photocatalytic degradation of 2-propanol in gas phase with different TiO2 catalysts

The photocatalytic efficiency of different TiO2 catalysts in the degradation of 2-propanol in gas phase has been studied. The obtained efficiencies have been compared considering the distribution of rutile–anatase phases, surface area, particle size, distribution of surface hydroxyl groups and Brönsted or Lewis acid centres. The catalysts used were Degussa-P25 (TiO2-P25), Hombikat, Millennium, Kemira and s/g-TiO2, a catalyst prepared by a sol–gel method.The best photocatalytic behaviours have been obtained with those catalysts with higher surface area and the presence of only anatase phase (Hombikat and Millennium). A progressive deactivation of TiO2-P25 and s/g-TiO2 has been observed during the photocatalytic process.FTIR studies indicated that degradation mechanisms depended on the catalyst employed. Deactivation processes observed in TiO2-P25 have been correlated with the formation of carboxylates.